#include <stdio.h>
#include <math.h>

typedef struct {
	double x, y;
} point;

double distance(point, point);
double area(double);

int main(int argc, char *argv[]) {
	point p1 = {1.0, 2.0};
	point p2 = {4.0, 6.0};
	double dist = distance(p1, p2);
	double a = area(dist);
	printf("The area is %f\n", a);
}

double distance(point p1, point p2) {
	double x = p1.x - p2.x;
	double y = p1.y - p2.y;
	return sqrt(x * x + y * y);
}

double area(double radius) {
	return M_PI * radius * radius;
}


